This invention relates to a method and an apparatus for manufacturing target products by processing units arranged at a plurality of manufacturing processes and, more particularly, to a method and an apparatus for manufacturing products capable of supervising or controlling carrying of intermediary, or semi-manufactured or processed products in order to efficiently allot or assign intermediary products to processing units.
The manufactures of various products including semiconductor devices are conducted with a plurality of manufacturing processes being combined. While carrying intermediary products via these processes, their assembling works are conducted. For instance, a method of manufacturing semiconductor devices comprises a series of processes, e.g., a die bonding process for mounting semiconductor components or elements on the lead frame, a cure process for setting resin used in the die bonding, a wire bonding process for connecting electrodes of the semiconductor components and leads of the lead frame using wires, a molding process for sealing wire-bonded regions using resin in the form of package, a cure process for setting the sealed resin by heating, and a bend process for bending leads projected from the resin, etc. For this reason, such an apparatus for manufacturing semiconductor devices is constituted that processing or manufacturing units, e.g., a mounter, a wire bonder, a molding unit, a cure unit, and a bend unit, etc. are arranged in succession from the upstream side of a carrying path for intermediary products. To the processing units at respective processes, carriers in which a plurality of lead frames on which unprocessed intermediary products are mounted are accommodated are carried or conveyed. By the load of the carriers, lead frames are taken one by one. Thus, predetermined processings will be conducted.
FIG. 1 is a block diagram showing a conventional example of a manufacturing apparatus in which processing units are arranged at a plurality of manufacturing processes, respectively as described above. This manufacturing apparatus includes four processes labeled I, II, III and IV: at the process I, four processing units a.sub.1, a.sub.2, a.sub.3 and a.sub.4 are disposed; at the process II, two processing units b.sub.1 and b.sub.2 are disposed; at the process III, four processing units c.sub.1, c.sub.2, c.sub.3 and c.sub.4 are disposed; and at the process IV, four processing units d.sub.1, d.sub.2, d.sub.3 and d.sub.4 are disposed. In this case, the processing units disposed in the same process carry out the same processing. The processing units at the respective processes are connected to a production supervisory computer 200. Thus, information indicative of output or the number of products, quality and working condition, etc. of respective units are delivered to the production supervisory computer 200. From the production supervisory computer 200, various instructions, e.g., kind of articles or goods to be processed, lot name, quantity, and processing condition, etc. are delivered every processes, and thus these units are controlled in response thereto. The intermediary products are carried and alloted to one processing unit of the groups of units at respective processes with they being as they are or they being accommodated in carriers in order of the processes I, II, III and IV. Thus, predetermined manufactured processings are implemented thereto. In this case, it is necessary to collate the kind of articles to which the production supervisory computer 200 gives an instruction for processing with the kind of articles that respective processing units process. For this reason, travel sheets or indication labels, e.g., magnetic cards, etc. are attached on intermediary products or carriers, and readers for automatically reading them and/or keyboards for artificially inputting information read therefrom are provided at respective processing units. Accordingly, for example, when an intermediary product or carrier is carried from the process I to the process II and the manufacturing processing is then implemented thereto, information indicative of kind of article or lot of the intermediary product or carrier processed is sent to the production supervisory computer 200. In response to this signal, the production supervisory computer 200 produces an instruction to transfer the intermediary product or carrier to the process III. Thus, the intermediary product or carrier is alloted or assigned to one of processing units C.sub.1, C.sub.2, C.sub.3 and C.sub.4 at the process III. Then, at these processing units C.sub.1, C.sub.2, C.sub.3 and C.sub.4 the indication label of the intermediary product or carrier carried is read. Thus, when the kind of the intermediary product or carrier is in correspondence with the kind of article alloted, the processing is initiated. Such an allocation has been conventionally carried out artificially.
However, with the conventional manufacturing method and apparatus, the following problems occur:
(1) Every time the kind or lot of the intermediary product is changed or exchange of the carrier occurs, communication with the production supervisory computer is required. Thus, the communication frequency becomes high, resulting in the possibility that an erroneous communication occurs.
(2) Since it is required to read the indication label every processing at respective processes, the reading frequency is high. Thus, there is apt to occur a circumstances such that reading is impossible due to the stain or missing or the indication label or the trouble of card reader, with the result that the system becomes confused.
(3) Where input of information of the kind of the article is artificially conducted, an erroneous input is likely to occur.
(4) Since the communication frequency becomes high and a large quantity of indication labels are required in the production of a large number of kinds and a small quantity, the above-mentioned troubles to are likely to occur, with the result that it takes much labor and time for their recovery.
(5) Since allocation of processing units within one process is artificially conducted, it is difficult to conduct an efficient allocation in consideration of the switching frequency of kind of article and/or the arrangement time for the processing unit.
As just described above, the conventional manufacturing method and apparatus have the problems that since indication labels indicative of kind of article, lot, or the like are read at respective processes, and thus the production ,supervisory computer supervises or controls carrying on the basis of this information, troubles are likely to occur and the improvement in the production efficiency is hindered.